A report released on Monday concluded that Gulf War syndrome is a legitimate illness suffered by more than 175,000 U.S. war veterans who were exposed to chemical toxins in the 1991 Gulf War.

The congressionally mandated report could help veterans who have battled the government for treatment of a wide range of unexplained neurological illnesses, from brain cancer to multiple sclerosis.

The Research Advisory Committee on Gulf War Veterans' Illnesses concluded that Gulf War illness is a physical condition distinct from the mental "shell shock" suffered by veterans in other wars. Some earlier studies had concluded it was not a distinct illness.

"Scientific evidence leaves no question that Gulf War illness is a real condition with real causes and serious consequences for affected veterans," said the committee, which has been looking into the problem since 2002.

The committee, composed of independent scientists and veterans, said Congress should boost funding for research on Gulf War veterans' health to at least $60 million per year.

"This is a national obligation, made especially urgent by the many years that Gulf War veterans have waited for answers and assistance," the committee said.

Gulf War illness affects at least one-fourth of the 700,000 U.S. troops who served in the 1991 effort to drive Iraq out of Kuwait, or between 175,000 and 210,000 veterans in all, the report found. Few have seen their symptoms improve over the past 17 years, the report said.

Many Gulf War veterans suffering these symptoms say they were met with skepticism when seeking treatment.

"Today's report brings to a close one of the darkest chapters of the 1991 Gulf War, and that is the legacy of Gulf War illness. For those who ever doubted that Gulf War veterans are ill, this report is definitive and exhaustive," said Anthony Hardie, a Gulf War veteran from Madison, Wisconsin.

Hardie was a 23-year-old sergeant at the time of the conflict. Today he works in Wisconsin's Veterans Affairs Department and suffers a host of ailments, including respiratory problems, fatigue and chronic widespread pain.

"The truth will prevail," said Adrian Atizado, assistant legislative director of the Disabled American Veterans, an advocacy group that represents 1.4 million veterans from the various conflicts in which the United States has fought.

"One can argue with merit that the federal government did hold back progress in allowing Gulf War veterans to seek health care and financial benefits," he said. "We hope now there will be a greater emphasis on finding effective treatments."

The panel found two possible causes: a drug given to troops to protect against nerve gas, known as pyridostigmine bromide, and pesticides that were used heavily during the war.

The panel said other possible causes could not be ruled out, including extensive exposure to smoke from oil-well fires and low-level exposure to sarin gas when captured Iraqi stocks were destroyed.

The U.S. government has spent roughly $440 million on Gulf War health research since 1994, but spending has declined in recent years and often is not focused on improving veterans' health, the committee said.